Google announced in May that it was working with MasterCard, Citi, and Sprint, which has the Nexus S 4G phone equipped with Near Field Communication technology on an embedded chip. MasterCard last Thursday gave a sneak peek of the Google Wallet application to analysts and reporters in New York City where representatives said the application was within weeks of being rolled out.

Google officials have said repeatedly that the rollout would start initially in San Francisco and New York City, although representatives could not be reached on Monday to discuss launch details. A MasterCard spokeswoman also said she could not confirm a Monday launch and said Google would need to provide such information.

The Google Wallet will require a user to have both a Nexus S 4G phone on the Sprint network and a MasterCard from Citi. Technology exists to allow an NFC sticker to be attached to other phones to make them capable of communicating with the PayPass terminals, but that approach is not considered as secure and it is not clear whether it will be used.

Meanwhile, TechCrunch posted a story Sunday with a photo of a notice of the various Google Wallet partners about the launch, saying it was set for Monday.

Two big concerns about NFC for a mobile wallet has been the shortage of NFC-ready phones in the U.S. market and lack of widespread deployment of payment terminals to read signals from specific phones. MasterCard said last week there are about 150,000 retail locations with the PayPass terminals, although some officials at the New York event said some of those terminals still need a software upgrade to work.

Another NFC-ready Android phone that supports Google Wallet, the Nexus Prime, is expected on Verizon Wireless next month.

Google's website describes a range of retail partners on the project, as well as how the Google Wallet requires a user to type in a PIN to activate the application each time.